Speedometer Fluctuating


I have a GNX dash and the VDO speedometer fulctuates at cruising speeds. I removed the lower cable and cleaned/lubed it but it still fluctuates. The dash was purchased new from Tom at gnxdash.com but I have not been able to contact him. I know its either the lower cable or the VSS that came with dash. Does anyone know how to contact Tom or know where he purchased the VSS? BTW I may also need a lower cable


More than anything else... It is probably the speedo-cable/or routing.

If the insert/core of the cable was tweeked at any time, it causes internal friction which causes the slow down/speed up rotational changes as it rubs inside. This will result in fluctuations at the gage. Lube will help, but not elliminate, a binding cable. Check the mounting under the dash as well... Did it come loose? Mine did and eventually, the little plastic piece on at end broke.

Even a new cable does not seem to fix it, as when mine broke, it seemed to get worse after replacement. Probably why the OEM cable was a 2 piece design.

To help mimimize the needle bounce, I had to ensure the cable under the car was lubed, routed properly, and supported by ALL factory hangers... I even had to add a few mounting points to my new cable to keep it steady. Make sure brackets hold the cable without crushing it, and make sure all the bends are smooth and gradual... no tight bends allowed!

I was never able to eliminate the problem, but over time and with adding brackes to secure it, it reduced the problem.